Ay, napakaseryoso ng tanong mo at deserve mo talaga ng proper legal advice dito, honestly, ito ang type of thing na kailangan mo mag-consult ng family lawyer para makasiguro na lahat ng steps ay tama and para sa best interest ng baby mo talaga. A few of my mum friends have gone through adoption processes pero iba-iba ang situations nila and the costs really depend on kung may cooperation from the biological parent or if may court battles involved, kaya talaga I can't give you exact numbers. Good luck sa journey mo, and sending strength, alam ko hindi easy ang lahat ng ito emotionally.